Stats Page Overhaul (#4292)

Co-authored-by: Amelia <77553571+Fesaa@users.noreply.github.com>

API/Middleware/ExceptionMiddleware.cs

@@ -3,6 +3,7 @@ using System.Net;
 using System.Text.Json;
 using System.Threading.Tasks;
 using API.Errors;
+using Kavita.Common;
 using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.Logging;
 
@@ -21,6 +22,11 @@ public class ExceptionMiddleware(RequestDelegate next, ILogger<ExceptionMiddlewa
         {
             await next(context); // downstream middlewares or http call
         }
+        catch (KavitaUnauthenticatedUserException)
+        {
+            context.Response.StatusCode = (int) HttpStatusCode.Unauthorized;
+            await context.Response.CompleteAsync();
+        }
         catch (Exception ex)
         {
             logger.LogError(ex, "There was an exception");